Apparatus and process for continuously texturing and post-setting yarns

ABSTRACT

Apparatus and process for continuous treatment of yarn wherein the yarn is passed through several heating devices, is falsetwisted, and is again passed through at least one of the heating devices to reduce its elasticity.

United States Patent [191 Ritter ,Eurte 4, 1974 APPARATUS AND PROCESS FOR CONTINUOUSLY TEXTURING AND POST-SETTING YARNS [75] Inventor: Helmut Ritter, Wattwil, Switzerland [73] Assignee: Heberlein & Co., AG, Gall,

Switzerland 22 Filed: Oct. 30, 1972 211 App]. NO. 302,476

[ 30] Foreign Application Priority Data Oct. 29, 1971 Switzerland... 15797/71 June 14, 1972 Switzerland 8884/72 [56] References Cited UNITED STATES PATENTS 2,900,783 8/1959 Carter et a1 57/34 HS 2,910,761 11/1959 Bley 57/34 HS X 3,041,813 7/1962 Enneking 57/34 HS 3,270,492 9/1966 Fitton et a1 57/157 TS 3,298,430 1/1967 Kodaira 28/62 X 3,382,658 5/1968 Mclntosh et a1 28/62 X 3,383,850 5/1968 Ratti 57/157 TS 3,501,904 3/1970 Batsch 57/34 HS 3,533,146 10/1970 Raschle et al. 28/62 3,738,017 6/1973 Raschle 57/34 HS X Primary Examiner-John W. Huckert Assistant ExaminerCharles Gorenstein Attorney, Agent, or Firm-Fitzpatrick, Cella, Harper & Scinto [5 7 ABSTRACT Apparatus and process for continuous treatment of yarn wherein the yarn is passed through several heating devices, is false-twisted, and is again passed through at least one of the heating devices to reduce its elasticity.

11 Claims, 4 Drawing Figures 29 AT C If 17 v 25 ,d

Jim 21 q- 18 s 4 liL-ts l7.

SHEET 2 (IF 2 PATENIEBM 4 mm This invention relates to apparatus for the continuous treatment of yarns, and more particularly, to apparatus for the continuous false-twist texturing and post-setting of yarns of thermoplastic synthetic material, and a process therefor.

It is known to produce elastic textured texile yarns by temporary high-twisting and heat-setting in the hightwisted state. It is furthermore known to subject the yarns obtained by such a false-twist texturing process to a further heat treatment in order to reduce their elasticity. Whilst, initially, this heat-setting was effected discontinuously, for example by exposing the textured yarn in the form of a loose wound-up package in a steam box, more recently, apparatuses for false-twist texturing have become known in which the yarn passes through a heating path before and after the twist imparter, the first heating step for heat-setting, the falsetwist and post-setting being effected continuously.

in one of these known apparatuses, for both heatsetting operations, the same heating device is used by passing the yarn through the heating device twice, i.e., before and after passage through the false-twist imparter (see French patent specification 1,353,893). This measure, however, presents the disadvantage that both heat-treatments are effected at the same temperature. It has, however, been found that, for obtaining good yarn quality, as a rule, the temperature during post-setting should be somewhat lower than during heat-setting of the false-twisted yarn. Furthermore, for heat-setting of the false-twisted yarn, generally, a longer heating path is necessary than for post-setting.

Furthermore, false-twist texturing devices are known in which the yarn, in order to obtain the longest possible heating path for heat-setting the false-twist, is passed through a heating device in one direction, then deviated by 180 and then passed through the same heating device in reverse direction (see, for example, British Patent 901,922). The disadvantage of this measure, however, consists in that twist is accumulated at the point of deviation between the first and the second passages of the yarn, which twist accumulation is very difficult to control and which may lead to irregularities in yarn quality.

I have conceived an apparatus for false-twist texturing and post-setting of yarns consisting of thermoplastic synthetic material continuously, in which the disadvantages of the known apparatuses are avoided.

This problem is resolved, according to my present invention, by composing the heating device of at least two heating units which may be adjusted to different temperatures and by arranging the yarn advancing and guiding means so that each yarn, before passage through the false-twist imparter, passes through both heating units which, together, form the heating path for heat-setting the false-twist, and, after passage through the false-twist imparter, passes again through the first heating unit which, when used alone, forms the heating path for post-setting.

Furthermore, additional possibilities are available for separately selecting the temperatures in the parts serving as the heat-setting path for the false-twist and as the post-setting heating path, respectively. It has been found that this can be effected in a simple way by exchanging or adding parts in a hot air box, for example.

By means of the apparatus of the present invention, 1 am able to obtain a relatively long heating path in which there is practically no deviation of the yarn, and whereby twist accumulation and the difiiculties associated therewith are avoided. Furthermore, the two heating units may be heated to different temperatures, i.e., the first heating unit, suitable for post-setting, may have a somewhat lower temperature than the second heating unit, whereas the temperature of the second heating unit should be high enough to assure molecular rearrangement during heat-setting of the yarn while in the false-twisted state.

The first unit of the heating apparatus may consist of a hot air box in which heat is transferred to the yarn by convection; and the second heating unit may also consist of a hot air box or of a contact heating element, for example of a slightly vaulted heated plate, rail or tube. In certain cases, it is also possible to use contact heating elements for both heating units.

A further aspect of the present invention is charac-.

terized in that, in a hot air box serving as the first heating unit, exchangeable tubes of heat-conductive material with different heat transfer properties and/or a heat insulating separation wall for dividing the hot air box into two closed chambers, each of which is provided for one yarn path, may be provided. The exchangeable tubes may primarily have different interior diameters. Thus, at equal hot air temperature for heating the same, a tube with a larger inner diameter, provides lower heat transfer to the yarn than a tube with a small interior diameter because of less intense radiation and because of greater air circulation. Furthermore, tubes consisting of materials with different heat conductivities may be used which may have either equal or different interior diameters; and a heat-insulating separation wall may be provided in the hot air box between tube sections serving as the two yarn paths, and the hot air temperature in the two thus-formed chambers may be selected by separate control means.

There has thusbeen outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art maybe better appreciated. There are, of

course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure -is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is an elevational view showing the construction of a first form of my invention;

FIG. 2 is a similar view illustrating the construction of a second form of the invention;

FIG. 3 illustrates a third form of the invention; and

FIG. 4 illustrates a fourth form of the invention.

Referring to FIG. 1, it will be seen that yarn 2 leaves d livery bobbin 1 and passes over deviation elements 27 and 28 and is drawn away by means of delivery rollers 3, whereupon it passes over deviation elements 24 and 25 and is introduced through inlet 4 into a heating box 5 closed on all sides and containing hot air. The box 5 forms a first unit of the heating device. Yam 2 leaves the box 5 through outlet 6 and enters into the second heating box 7, arranged close to heating box 5, through inlet 8. In order to avoid temperature decrease in the yarn, a short removable tube 9 is provided between the outlet 6 and inlet 8. Yam 2 leaves heating box 7 through outlet MD, and successively passes over deviation elements 11 and 12 through the false-twist imparter 13, the deviation elements 14 and 29, and rollers l5, and enters into the heating box 5 for a second time through inlet 16, leaving the same through outlet 17, whereupon it is fed to the wind-up device 22 via deviation elements 18 and 19, delivery rollers 20 and deviation element 21.

in the example shown in FIG. 2, the yarn path and references of which correspond to those of H6. 1, instead of the second heating box 7, a slightly vaulted, electrically heated plate 23 is provided over which the yarn 2 is passed in direct contact. This form of the invention has the advantage that, in certain cases, the use of the heating plate 23 as final stage of the heating path for heatsetting the false-twist, permits me to obtain other characteristics in the hand of the yarn than when using heating box 7.

According to H6. 3, two axially parallel aluminum tubes 33 and 34 are exchangeably fixed in the inlets and outlets 4 and 6, and 16 and 17, respectively, of the top and bottom parts of box 5, which tubes are heated by the hot air surrounding them in the box. in the first passage, i.e., in the heating path for setting the falsetwist, the yarn 2 passes through tube 33 and, in the second passage, i.e., on the post-setting path, through tube 34. The interior diameters of the tubes 33 and 34 are different, wherefore the quantity of heat radiated into the yarns from the tube walls is also different. Instead of aluminum tubes with different diameters, tubes consisting of material with different heat conductivities, for example an aluminum and a copper tube, may be used. It is furthermore possible to provide the outer faces of one tube with ribs for enlarging the heat transfer surface from the hot air to the tube wall. By insertion of tubes with different heat transfer properties, the setting temperatures on the false-twist texturing path and the post-setting path may be adapted to the needs of particular cases.

According to H6. 4, which only shows the hot air box 5, the same is divided into two closed chambers 31 and 32 by means of a heat-insulating wall inserted between tubes 33 and 34, in which chambers there is hot air of different temperatures so that the tubes 33 and 34- are heated to different temperatures. The temperature in the two chambers 31, 32 may be selected according to necessity by means of separate control devices (not shown).

The apparatus of the present invention may be used in the form of a machine with a plurality of treatment stations arranged beside each other on both sides'of a frame, the number being for example, 160, i.e., 80 on each side of the frame, said machine having a twist imparter for each treatment station. The horizontal walls of the heating boxes 5 and '7, extending over the whole length of the frame, may have a corresponding number of yarn inlets and outlets. the heating box may also be equipped with separate tubes for the passage of each individual yarn. If, instead of the heating box 7, a heatingplate 23 is used, on each side of the machine, several heating plates extending over a certain number of, for example 10, treatment stations may be used.

It should be understood that in the claims appended to this specification, where the yarn path is defined as through a heating unit and a heating unit is defined as a contact heating element, then the yarn is deemed to pass in direct contact with such contact heating element.

The apparatus, according to the present invention, is particularly suitable for false-twist texturing and postsetting of multifilament yarns of polyamides, polyester, polyacrylonitrile, polyolefines and acetate rayon. During treatment of yams of polyamide, 6.6 or polyester filaments, for example, the temperature of the first heating unit which serves as post-setting heating path during the second passage of the yarn therethrough may, according to the required extent of reduction of elasticity, be between lQ and 210C whereas, in the second heating unit which serves as terminal stage of the heating path for heat-setting the false-twist, the temperature should be approximately between 219? and 239C to effect molecular rearrangement in the filament material.

I believe that the construction and operation of my novel apparatus will now be understood and that the advantages thereof will be fully appreciated by those persons skilled in the art.

I claim:

1. Apparatus for continuous false-twist texturing and post-setting of yarns of thermoplastic synthetic material comprising false-twist means, heating means and yarn delivering and guiding means, said heating means consisting of two separate hot air boxes adjustable to different temperatures each box having yarn inlet and outlet means and said yarn delivery and guiding means passing each yarn sequentially first through both hot air boxes to effect setting of the false-twist then through the false-twist means and again through the first hot air box to effect post-setting of the yarn.

2. Apparatus according to claim 1, characterized in that the yarn outlet means (6) on the lower face of the hot air box (5) forming the first heating unit and the yarn inlet means (8) on the upper face of the hot air box (7), forming the second heating unit, are connected by means of a tube (9).

3. Apparatus according to claim 1, characterized in that, in the hot air box (5) serving as first heating unit, separate exchangeable tubes (33, 34) of heatconductive material with different heat transfer properties are provided, each for one of the yarn paths through said first hot air box.

4. Apparatus according to claim 1, characterized in that, in the hot air box (5) serving as first heating unit, a heat-insulating separation wall (30) is provided for separation of the hot air box into two chambers (31,32), each for one of the yarn paths.

5. Apparatus for continuous false-twist texturing and post-setting of yarns of thermoplastic synthetic material comprising false-twist means, heating means and yarn delivering and guiding means said heating means consisting of two separate hot air boxes adjustable to different temperatures each box having yarn inlet and outlet means, separate exchangeable tube means forming paths for the yarn in each box, and said delivery and guiding means passing each yarn sequentially through tube means in both hot air boxes to effect setting of the false-twist, then through the false-twist means and through tube means in the first hot air box to effect post-setting of the yarn.

6. Apparatus according to claim 5, wherein the first hot-air box has separate exchangeable tubes consisting of material of different heat-conductivities for the false-twist texturing path and for the post-setting path of the yarn.

7. Apparatus according to claim 5, wherein the first air box has separate exchangeable tubes of different interior diameters for the false-twist texturing path and for the post-setting path of the yarn.

8. Apparatus according to claim 5, wherein the first air box is separated into two chambers by a wall of heat-insulating material and exchangeable tube means for the false-twist path and for the post-setting path of the yarn extend through the respective chambers formed by the wall.

9. Apparatus according to claim 5, characterized in that at least one of the tube means for the two yarn paths in said first box is exteriorly provided with ribs.

10. Process for continuously false-twist texturing and post-setting of yarns of thermoplastic synthetic material which comprises passing the yarn, before passage through the false-twist imparter, through two heating units which together form the heating path for heatsetting the false-twist and wherein the first heating element is set to a lower temperature than the second heating element and passing the yarn, after passage through the false-twist imparter, once more through the first heating unit for post-setting the yarn.

11. Process according to claim 10, characterized in that, when yarn of polyamide 6 or polyester is treated, the first heating unit is set to a temperature of between L612 and 2 112C, and the second heating unit is set to a temperature of between 210 and 230C, and after passage through the false-twist imparter, the yarn is passed again through the first heating unit. 

1. Apparatus for continuous false-twist texturing and postsetting of yarns of thermoplastic synthetic material comprising false-twist means, heating means and yarn delivering and guiding means, said heating means consisting of two separate hot air boxes adjustable to different temperatures each box having yarn inlet and outlet means and said yarn delivery and guiding means passing each yarn sequentially first through both hot air boxes to effect setting of the false-twist then through the false-twist means and again through the first hot air box to effect postsetting of the yarn.
 2. Apparatus according to claim 1, characterized in that the yarn outlet means (6) on the lower face of the hot air box (5) forming the first heating unit and the yarn inlet means (8) on the upper face of the hot air box (7), forming the second heating unit, are connected by means of a tube (9).
 3. Apparatus according to claim 1, characterized in that, in the hot air box (5) serving as first heating unit, separate exchangeable tubes (33, 34) of heat-conductive material with different heat transfer properties are provided, each for one of the yarn paths through said first hot air box.
 4. Apparatus according to claim 1, characterized in that, in the hot air box (5) serving as first heating unit, a heat-insulating separation wall (30) is provided for separation of the hot air box into two chambers (31,32), each for one of the yarn paths.
 5. Apparatus for continuous false-twist texturing and post-setting of yarns of thermoplastic synthetic material comprising false-twist means, heating means and yarn delivering and guiding means said heating means consisting of two separate hot air boxes adjustable to different temperatures each box having yarn inlet and outlet means, separate exchangeable tube means forming paths for the yarn in each box, and said delivery and guiding means passing each yarn sequentially through tube means in both hot air boxes to effect setting of the false-twist, then through the false-twist means and through tube means in the first hot air box to effect post-setting of the yarn.
 6. Apparatus according to claim 5, wherein the first hot-air box has separate exchangeable tubes consisting of material of different heat-conductivities for the false-twist texturing path and for the post-setting path of the yarn.
 7. Apparatus according to claim 5, wherein the first air box has separate exchangeable tubes of different interior diameters for the false-twist texturing path and for the post-setting path of the yarn.
 8. Apparatus according to claim 5, wherein the first air box is separated into two chambers by a wall of heat-insulating material and exchangeable tube means for the false-twist path and for the post-setting path of the yarn extend through the respective chambers formed by the wall.
 9. Apparatus according to claim 5, characterized in that at least one of the tube means for the two yarn paths in said first box is exteriorly provided with ribs.
 10. Process for continuously false-twist texturing and post-setting of yarns of thermoplastic synthetic material which comprises passing the yarn, before passage through the false-twist imparter, through two heating units which together form the heating path for heat-setting the false-twist and wherein the first heating element is set to a lower temperature than the second heating element and passing the yarn, after passage through the false-twist imparter, once more through the first heating unit for post-setting the yarn.
 11. Process according to claim 10, characterized in that, when yarn of polyamide 6.6 or polyester is treated, the first heating unit is set to a temperature of between 160* and 210*C, and the second heating unit is set to a temperature of between 210* and 230*C, and after passage through the false-twist imparter, the yarn is passed again through the first heating unit. 